Shuttle Discovery Launches Space Station's Largest Lab
Space shuttle Discovery thunders off the launch pad at NASA's Kennedy Space Center in Florida on May 31, 2008 to begine the STS-124 mission.
Credit: NASA TV

Editor's Note: This story was updated at 5:25 p.m. EDT.

CAPE CANAVERAL, Fla. - NASA?s shuttle Discovery rocketed into space Saturday with a massive Japanese laboratory bound for the International Space Station.

Discovery shot up into the sky at 5:02 p.m. EDT (2102 GMT) from its seaside Launch Pad 39A here at NASA?s Kennedy Space Center carrying what will soon be the largest single room aboard the space station - the tour bus-sized main cabin of the Japan?s Kibo (?hope? in Japanese) laboratory.

?While we've all prepared for this event today, the discoveries from Kibo will definitely offer hope for tomorrow,? said Discovery?s commander Mark Kelly just before launch. ?Now stand by for the greatest show on Earth.?

During their planned 14-day mission, Discovery?s seven crewmembers will perform three spacewalks to install the $1 billion Kibo laboratory, relocate its smaller storage cabin from its current perch to the main room, and activate the laboratory?s robotic arm. The shuttle is slated to dock at the International Space Station (ISS) on Monday afternoon.

Watching the launch here was Kelly?s identical twin brother, Scott Kelly, who is also a veteran astronaut. Their father Richard celebrated his 68th birthday while his son Mark launched into space.

?I?m excited for him - it?s an amazing experience,? Scott Kelly, a veteran spaceflyer, told SPACE.com this morning. ?I think it?s a unique privilege to not only fly in space but then have your brother that you can talk about it with and he understands exactly what you?re talking about ?cause he?s shared those experiences and memories.?

Japan?s ?hopes? reach space

Discovery?s STS-124 mission is the second of three planned shuttle flights to bring all of Kibo?s elements into space. It follows the shuttle Endeavour?s March 2008 flight, which delivered the small storage room, and precedes a planned spring 2009 mission to deliver Kibo?s porch-like external platform.

The launch of Kibo?s main element represents the fruition of more than 20 years of work and planning by Japan to add its own segment to the space station. The new module is about 37 feet (11 meters) long and about 14.4 feet (4.4 meters) wide. It weighs about 32,000 pounds (14,514 kg).

?It shows ISS is coming into the stage of the truly international,? said Yoshiyuki Hasegawa, Japanese Experiment Module program manager. ?This Kibo is known for the Japanese people, even child and old man and government senator. Even my mother knows that Kibo is the international station and made in Japan.?

Japan?s stake in Discovery?s mission is embodied by crewmember Akihiko Hoshide, a Japan Aerospace Exploration Agency astronaut who will serve as the resident Kibo expert when he and his crewmates work to install the lab on the ISS.

?This is a big step for the Japanese community, the science community especially, because that means that they can start their own science,? Hoshide said before launch. ?It?s a big milestone for Japan.?

Crew?s dreams

Other STS-124 astronauts include pilot Ken Ham, mission specialist Karen Nyberg - who became the 50th woman to fly in space with today?s launch - and fellow NASA spaceflyers Rob Garan, Mike Fossum and Greg Chamitoff. Chamitoff will stay aboard the orbital outpost after Discovery departs, replacing U.S. astronaut Garrett Reisman as a member of the ISS?s three-man Expedition 17 crew. Reisman is slated to return with Discovery during its planned June 14 landing.

?The idea of just living in space for a long period of time and knowing what it?s like to live there, I think, is one thing I?m looking forward to,? Chamitoff, a first-time spaceflyer, said before flight. ?That?s going to be an amazing experience up there just to have one part of one step of getting humanity up to the stars.?

Besides dropping off the Kibo lab and Chamitoff, Discovery is hauling a few other important pieces of cargo.

The shuttle is carrying a replacement pump to fix the space station?s faulty toilet. The orbital loo, the only one on the ISS except for the facilities on the docked Soyuz spacecraft, is working partially, though it is inconvenient and time-consuming. Space station residents are hoping the new pump will fix the problem, though previous spare pumps have so far failed to do so.

Discovery is also carrying an action figure of the Buzz Lightyear character from the 1995 Disney-Pixar movie ?Toy Story.? By flying into space, the toy will perform educational demonstrations for kids and also fulfill Buzz?s goal of reaching ?infinity and beyond.?

Landmark trip

Today?s launch marks the third of up to five shuttle flights planned for the busy 2008 year. Discovery?s voyage is the 123rd space shuttle mission to fly and the 26th trip to the ISS. NASA aims to retire the shuttle program in 2010, with just 11 more shuttle flights planned to complete space station construction and overhaul the Hubble Space Telescope. Discovery?s STS-124 mission marks the shuttle?s 35th trip to space.

In an unusual move, Discovery launched without its sensor-tipped robotic arm inspection boom aboard, in order to make room for its giant Japanese payload, the largest ever launched to the ISS.

Since Columbia?s tragedy in 2003, astronauts usually spend the day following launch using the boom to inspect their orbiter?s heat shield tiling for damage such as that which caused the earlier disaster. Luckily, the previous shuttle flight, Endeavour?s STS-123 mission, left Discover?s boom waiting for it on the space station.

?After we launch, before we rendezvous, we?re going to use the shuttle arm and the camera that?s on the end of the shuttle arm to do as much of the rudimentary inspection as we can of the wings of the orbiter,? Ham said in a preflight interview. ?After we undock, we will do the traditional detailed survey of the thermal protection system of the orbiter so that we can guarantee that we are safe to enter.?

The shuttle is scheduled to dock with the ISS at 1:54 p.m. EDT (1754 GMT) on Monday.

Upon the shuttle's arrival in space, mission control congratulated Kelly and his team.

"It's good to be back, and it's good for everybody to be here," Kelly replied

NASA is broadcasting Discovery's STS-124 mission live on NASA TV. Click here for SPACE.com's shuttle mission updates and a live NASA TV feed.